<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>将 object 对象中的 key 和 value 互换</title>
</head>

<body>
  <script>
    var object = {
      key: 12,
      value: 2
    }
    for (let k in object) {
      let value = object[k];
      object[value] = k;
      delete object[k];
    }
    console.log(object);
  </script>
</body>

</html>